The present study evaluates the performances of a rammed earth (RE) structure under seismic loading and its reinforcement by using finite element simulations. First, the pertinence of the numerical ...model was evaluated through the simulation of an experimental test conducted on a 0.5-scale house and presented in the literature. A full 3D model, based on solid elements, and a 3D surface model based on shell elements were conducted. The effects of interface stiffness on the natural frequencies and on the non-linear dynamic behavior were examined. It was found that the interfaces played an important role to well reproduce the experimental results. Reinforcement techniques, such as horizontal reinforced concrete belt beam at the top or/and the middle height, and the internal reinforced concrete columns were also simulated and their benefits under seismic loading were conducted. The results obtained showed that these reinforcements enhanced the seismic capacity of RE house. The Rayleigh damping, which has been rarely addressed in the rammed earth structures, was also investigated.
•Evaluation of the performances of a RE structures under seismic loading by FEM.•FEM was based on a full 3D model and a 3D surface model.•Improvement solutions for RE under earthquake were studied.•Rayleigh damping was also investigated.
Fibre-reinforced polymers (FRPs) and textile-reinforced concretes (TRCs) are becoming increasingly common solutions for strengthening masonry walls. This study focuses on different approaches for ...modelling the behaviour of hollow concrete block masonry walls strengthened with FRPs and a TRC subjected to in-plane loading. Specifically, the masonry is modelled using the heterogeneous approach, wherein the damage post-peak softening behaviours of both bricks and mortar are considered, as this approach is appropriate for material and structure scales. To model the FRP/TRC-reinforced masonry walls, the reinforcements (FRPs/TRC) are perfectly connected to the substrate. Although the homogeneous approach is proposed to model the FRPs with linear elastic behaviour and is shown to be appropriate for modelling the FRP-reinforced masonry walls, the TRC is modelled using the heterogeneous approach, allowing for the real contribution of the filaments to be expressed through an ‘efficiency factor’. The numerical results show that this factor has a significant influence on the behaviour of the TRC and therefore, on the overall behaviour of the TRC-reinforced walls. However, the ‘efficiency factor’ of the TRC sample is significantly higher than that of the TRC in the strengthened wall. This result confirms that the choice of the heterogeneous approach to model the TRC in our case is appropriate. Moreover, it verifies that it is impossible to transpose this global factor from the material scale (uniaxial tensile stress) to the structure scale when the application target is a masonry wall (multi-axiality, and therefore, complexity of the stress). Consequently, the constitutive laws of the TRC composite obtained through only direct uniaxial tensile characterization procedures are insufficient to enable a suitable restitution of the overall behaviour of the masonry reinforced with the TRC. In addition, regardless of the nature of the reinforcement, the overall behaviours of the masonry walls reinforced with the FRPs/TRC are governed by both the axial stiffness of the reinforcement and the compressive strength of the masonry substrate.
Rammed earth (RE) is a construction material which is made by compacting the soil in a formwork. This material is attracting the attention of the scientific community due to its sustainable ...characteristics. Among different aspects to be investigated, the seismic performance remains an important topic which needs advanced investigations. The existing studies in the literature have mainly adopted simplified approaches to investigate the seismic performance of RE structures. The present paper adopts a numerical approach to investigate the seismic behavior of RE walls with an L-form cross-section. The 3D FEM model used can take into account the plasticity and damage of RE layers and the interfaces. The model was first validated by an experimental test presented in the literature. Then, the model was employed to assess the seismic performance of a L-form wall of a RE house at different amplitudes of earthquake excitations. Influences of the cross-section form on the earthquake performance of RE walls were also investigated. The results show that the L-form cross-section wall has a better seismic performance than a simple rectangular cross-section wall with similar dimensions. For the L-form cross-section wall, the damage observed concentrates essentially on the connection between two flanges of the wall.
Environmental, social, and governance (ESG) disclosure becomes vital for banks to be transparent and accountable for their investments and lending decisions to shareholders, regulators, and society. ...The potential enhancement of shareholder value through ESG disclosure is still inconsistent. Empirical studies on the association between ESG disclosure and financial performance are mixed and limited in emerging economies. This study aims to examine whether ESG disclosure impacts the financial performance of 24 Vietnamese commercial banks in terms of return on assets (ROA), return on equity (ROE), and net interest margin (NIM). The study uses the feasible generalized least squares estimation method based on panel data from 2018 to 2022. The study employs content analysis on 12 themes related to environmental, social, and governance pillars to score policy disclosure based on the Fair Finance Guide Methodology. The results highlight the positive effects of ESG policy disclosure, individual environment disclosure (E), and individual governance disclosure (G) on bank financial performance. Notably, ESG, E, and G have the largest influence on ROE, with coefficients of 0.051, 0.036, and 0.027, respectively, at a 5% significance level. However, the study does not provide evidence of a statistically significant association between social disclosure and financial performance. These results provide empirical evidence for regulators and bank managers to shape ESG policies and practices aligning with international standards. AcknowledgmentESG disclosure score of 11 banks as primary data in this study is conducted under the project coordinated by the Fair Finance Vietnam coalition, as part of Fair Finance International.
Black soldier fly larvae (BSFL), high-fat-containing insects, are a promising non-edible feedstock for biodiesel production. Extracting fat from BSFL biomass for biodiesel production by using ...traditional methods requires a high amount of solvent, long extraction time, and thermal conditions. To address these limitations, this study proposed an enzyme-assisted extraction method for extracting fat from BSFL biomass for biodiesel production. Different proteases were used to pretreated BSFL biomass prior to the extraction by n-hexane. Among the tested enzymes, Protamex was the most effective for the pretreatment, resulting in the highest fat yield (2.2-fold increase in the fat yield, compared with the extraction without enzymatic treatment). The extraction of insect fat using Protamex-assisted pretreatment was then optimized using response surface methodology (RSM). A four-factor, three-level Box–Behnken design was employed to optimize the factors for the highest fat yield using 27 experimental runs. The optimized conditions were water-to-biomass weight ratio of 4.33:1, enzyme amount of 3.85%, enzymatic treatment temperature of 38.1 °C, and enzymatic treatment time of 4.27 h for a maximum fat yield of 36.09%. The extracted BSFL fat was then used as feedstock for producing biodiesel. Most properties of the synthesized biodiesel met American Society for Testing and Materials (ASTM) specification D6751 and European standard EN 14214. The enzyme-assisted extraction process was then proposed for use in large-scale operations to evaluate its economic feasibility, revealing promising industrial applications. This study suggests that the enzyme-assisted extraction is an efficient method for extracting insect fat, and the extracted fat has potential for use as oil for biodiesel production.
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•Enzyme-assisted extraction was successfully developed to extract fat from insect.•The extraction conditions were optimized using response surface methodology.•Enzyme-assisted extraction using Protamex and n-hexane improved the fat yield.•All properties of black soldier fly larvae biodiesel met the standard EN 14214.•The proposed process shows promising industrial applications.
Multifocal (MF) and multicentric (MC) breast cancers are referred to as synchronous, multiple ipsilateral breast cancers; however, the definitions vary among the literature, which has made ...understanding and analyzing these diseases challenging.
The incidence ranges from 1% to 60%, with a higher prevalence in pre-menopausal women. MF and MC breast cancers, compared with unifocal breast cancers, tend to be more aggressive and are associated with lower survival rates, higher recurrence, and lymph node metastasis. Typically, patients with MF/MC breast cancers are treated with radical surgery, while breast conservation therapy may also be considered. Investigations have focused on elucidating the distinct biological features of MF/MC breast cancers, including the clonality of the cancers, the genetic alterations, and the impact of these features on disease aggressiveness and patient prognosis.
These findings will broaden the understanding of these breast cancer subtypes and aid in the development of more tailored treatment plans for patients.
Listeria monocytogenes
is a Gram-positive, intracellular pathogen responsible for the highly fatal foodborne illness listeriosis. Establishing intracellular infections requires the coordinated ...expressions of a variety of virulence factors, such as the pore-forming toxin listeriolysin O (LLO), in response to various intra- and extracellular signals. For example, we previously reported that
L. monocytogenes
differentially modulated LLO production in response to exogenous propionate, a short chain fatty acid either used in salt form as a human food ingredient or produced endogenously by gut microbial fermentation. Therefore, propionate is likely a continuously present signal throughout the
L. monocytogenes
transmission and infection process. However, little is known about the role of propionate in modulating
L. monocytogenes-
host interactions. Here we investigated the impact of propionate treatment on
L. monocytogenes
intracellular infections using cell culture infection models. Propionate treatment was performed separately on
L. monocytogenes
or host cells before or during infections to better distinguish pathogen-versus-host responses to propionate. Intracellular CFU in RAW264.7 macrophages and plaque diameters in L-fibroblasts were measured as proxy for intracellular infection outcomes. Nitrite levels and cellular morphology were also measured to assess host responses to propionate. We found that propionate pretreatment of anaerobic, but not aerobic,
L. monocytogenes
significantly enhanced subsequent intracellular infections in both cell types and nitrite production by infected macrophages. Propionate treatment of uninfected macrophages significantly altered cell morphology, seen by longer cells and greater migration, and reduced nitrite concentration in activated macrophages. Treatment of macrophages with propionate prior to or during infections significantly inhibited intracellular growth of
L. monocytogenes
, including those pre-treated with propionate. These results showcased an opposing effect of propionate on
L. monocytogenes
intracellular infections and strongly support propionate as an important signaling molecule for both the pathogen and the host cell that can potentially alter the outcome of
L. monocytogenes
-host interactions.
This paper focuses on local people’s participation in the development of ecological cultural tourism in the Vam Nao reservoir area of An Giang Province, located approximately 180 kilomteres southeast ...of Ho Chi Minh City, Vietnam. Building on experiences of several countries on how to involve local people in natural resource management and ecotourism development, we interviewed 95 in-depth stakeholders related to natural resource management, tourism, environment, and people’s participation; distributed questionnaires to 340 tourists; and synthesised field survey data from 500 online visitor surveys. On the basis of analysis and evaluation of these materials, this paper suggests a new policy on tourism for An Giang provincial leaders involving preservation of local cultural values as support for ecological and cultural tourism in the studied area. In the last section, the paper makes recommendations for increasing community participation in areas similar to the one studied herein.
Vietnam is one of the world’s top two rice exporting countries. However, rice cultivation is the primary source of agriculture’s greenhouse gas (GHG) emissions in Vietnam. In particular, strategies ...are required to reduce GHG emissions associated with the application of organic and inorganic fertilisers. The objective of this study was to assess the effects of various combinations of biochar (BIOC), compost (COMP) and slow-release urea (SRU) on methane (CH
4
) and nitrous oxide (N
2
O) emissions. In total, 1170 gas samples were collected from closed gas chambers in rice paddies at Thinh Long commune and Rang Dong farm in northern Vietnam between June and October 2014. The gas samples were analysed for CH
4
-C and N
2
O-N fluxes using gas chromatography. The application of BIOC alone resulted in the lowest CH
4
emissions (4.8–59 mg C m
−2
h
−1
) and lowest N
2
O emissions (0.15–0.26 µg N m
−2
h
−1
). The combined application of nitrogen–phosphorus–potassium (NPK) + COMP emitted the highest CH
4
(14–72 mg C m
−2
h
−1
), while ½NPK + BIOC emitted the highest N
2
O (1.03 µg N m
−2
h
−1
in the TL commune), but it was the second lowest (0.495 µg N m
−2
h
−1
) in the RD farm. Green urea and orange urea reduced N
2
O emissions significantly (
p
< 0.05) compared to white urea, but no significant differences were observed with respect to CH
4
emissions. SRU fertilisers and BIOC alone measured the lowest greenhouse gas intensity, i.e. <2.5 and 3 kg CO
2
eq. kg
−1
rice grain, respectively. Based on these results, application of fertilisers in the form of BIOC and/or orange or green urea could be a viable option to reduce both CH
4
and N
2
O emissions from rice paddy soils.
Tumor cells are malignant derivatives of normal cells. There are characteristic differences in the mechanophysical properties of normal and tumor cells, and these differences stem from the changes ...that occur in the cell cytoskeleton during cancer progression. There is a need for viable whole blood processing techniques for rapid and reliable tumor cell detection that do not require tagging. Micropore biosensors have previously been used to differentiate tumor cells from normal cells and we have used a micropore-based electromechanical transducer to differentiate one type of tumor cells from the other types. This device generated electrical signals that were characteristic of the cell properties. Three non-small cell lung cancer (NSCLC) cell lines, NCl-H1155, A549 and NCI-H460, were successfully differentiated. NCI-H1155, due to their comparatively smaller size, were found to be the quickest in translocating through the micropore. Their translocation through a 15 μm micropore caused electrical pulses with an average translocation time of 101 ± 9.4 μs and an average peak amplitude of 3.71 ± 0.42 μA, whereas translocation of A549 and NCI-H460 caused pulses with average translocation times of 126 ± 17.9 μs and 148 ± 13.7 μs and average peak amplitudes of 4.58 ± 0.61 μA and 5.27 ± 0.66 μA, respectively. This transformation of the differences in cell properties into differences in the electrical profiles (i.e. the differences in peak amplitudes and translocation times) with this electromechanical transducer is a quantitative way to differentiate these lung cancer cells. The solid-state micropore device processed whole biological samples without any pre-processing requirements and is thus ideal for point-of-care applications.
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